| ML Securities Limited | Administrative & support | 2010 |
| MLC Haulage Ltd | Other services | 2018 |
| MLR Housing Ltd | Real estate | 2023 |
| MLT Electrical Limited | Construction | 2022 |
| MLT Group Limited | Wholesale & retail | 2026 |
| MM Boiler & Electrical Solutions Ltd | Construction | 2018 |
| MM Green Limited | Real estate | 2020 |
| MM Interior Solutions Ltd | Construction | 2025 |
| MM Properties Solutions Ltd | Real estate | 2023 |
| Mm&Zee Ltd | Wholesale & retail | 2024 |
| Mman Ltd | Real estate | 2022 |
| MMB Enterprise Ltd | Wholesale & retail | 2021 |
| MMB Removal Ltd | Wholesale & retail | 2022 |
| MMD Consulting Limited | Professional & scientific | 2026 |
| MMH Real Estate Ltd | Real estate | 2026 |
| MMJ (London) Property Limited | Other services | 2022 |
| MMK Technology Services Ltd | Information & communication | 2022 |
| Mmnm Services Limited | Professional & scientific | 2025 |
| MMR Freight Ltd | Transport & logistics | 2026 |
| MMR Trading Ltd | Wholesale & retail | 2019 |
| Mmrmcars Limited | Wholesale & retail | 2014 |
| Mmsk Stores Limited | Wholesale & retail | 2021 |
| MMU Brickwork Ltd | Construction | 2023 |
| MMV IT Solutions Limited | Information & communication | 2022 |
| Mmyousuf Ltd | Wholesale & retail | 2025 |
| MN Electrical Ltd | Construction | 2025 |
| MN Skip Company Ltd | Water & waste | 2026 |
| MNA Management Ltd | Professional & scientific | 2018 |
| MNC Estates Ltd | Financial services | 2024 |
| Mngl Limited | Construction | 2017 |
| MNM Billericay Ltd | Hospitality | 2024 |
| MNM System Ltd | Information & communication | 2020 |
| MNZ Construction Services Ltd | Administrative & support | 2024 |
| MO Pharma Ltd | Health & social care | 2020 |
| Mo&Me Films Limited | Information & communication | 2024 |
| Mo&Mo Property Ltd | Real estate | 2020 |
| Mo's Driving Academy Limited | Education | 2024 |
| Mobcat Limited | Construction | 2024 |
| Mobile 365 Ltd | Wholesale & retail | 2023 |
| Mobile AR Vehicleservices Ltd | Wholesale & retail | 2024 |
| Mobile Car Mechanic Ltd | Wholesale & retail | 2024 |
| Mobile Phix Ltd | Wholesale & retail | 2024 |
| Mobile Signal Services Ltd | Wholesale & retail | 2021 |
| Mobile Therapies Ltd | Health & social care | 2024 |
| Mobilink Ltd | Wholesale & retail | 2025 |
| Mobite Group Limited | Wholesale & retail | 2024 |
| Mobrex Limited | Manufacturing | 2025 |
| Mobutu Motors Ltd | Wholesale & retail | 2020 |
| Modaamana Ltd | Health & social care | 2011 |
| Model Power Boat Association | Arts & recreation | 1979 |
| Modenva MK Limited | Wholesale & retail | 2025 |
| Modern Domestic Appliances Ltd | Other services | 2024 |
| Modern FIX Dorut Ltd | Construction | 2026 |
| Modern UK Living Ltd | Wholesale & retail | 2024 |
| Moderna Contracts Limited | Construction | 1980 |
| Modest Aura Ltd | Arts & recreation | 2026 |
| Modish Mart Ltd | Wholesale & retail | 2023 |
| Modular Engineering Ltd | Administrative & support | 2016 |
| Modutec Engineering Limited | Professional & scientific | 2018 |
| Moga Transport Service Ltd | Transport & logistics | 2019 |
| Mogok Ruby Ltd | Manufacturing | 2026 |
| Mohamad KRD Ltd | Wholesale & retail | 2025 |
| Mohammad ALI Limited | Real estate | 2025 |
| Mohammad Mahzeer Ltd | Information & communication | 2019 |
| Mohammed Emdad Hussain Limited | Transport & logistics | 2017 |
| Mohammed Faraz Enterprise Centre Ltd | Real estate | 2018 |
| Mohammed KR Ltd | Wholesale & retail | 2026 |
| Mohammed KRD Ltd | Wholesale & retail | 2026 |
| Mohammed Mustafa Ltd | Wholesale & retail | 2025 |
| Mohan & Sons Investment Ltd | Real estate | 2024 |
| Mois Tiling Limited | Construction | 2017 |
| Mojadel Company Limited | Information & communication | 2011 |
| Mojo Infinity Limited | Real estate | 2019 |
| Mojo One Limited | Financial services | 2019 |
| Mojo Security Limited | Information & communication | 2015 |
| Mokaeus Property Services Limited | Real estate | 2020 |
| Mokni Plumbing & Heating Ltd | Construction | 2021 |
| Moku Space Limited | Construction | 2023 |
| Mold Class Ltd | Construction | 2021 |
| Moldaccounting Ltd | Professional & scientific | 2017 |
| Moldconstruction Ltd | Construction | 2019 |
| Moldovian Wine Ltd | Wholesale & retail | 2020 |
| Moldstar Construction Ltd | Manufacturing | 2024 |
| Moldstar Development Ltd | Construction | 2024 |
| Moldstruct Ltd | Construction | 2022 |
| Molla Design Property Ltd | Real estate | 2024 |
| Mollitiam Partners Limited | Professional & scientific | 2021 |
| Mona's Food Ltd | Hospitality | 2024 |
| Monc Construction Group Ltd | Manufacturing | 2026 |
| Mondego Limited | Construction | 2022 |
| Money Plant Ltd | Real estate | 2024 |
| Money Save Property Ltd | Real estate | 2024 |
| Money Valley UK Ltd | Professional & scientific | 2021 |
| Mongan Plumbing and Heating Ltd | Construction | 2026 |
| Monic Construction Ltd | Construction | 2016 |
| Monks Wholesale Limited | Manufacturing | 2012 |
| Monr Ltd | Real estate | 2018 |
| Monsta Empire Limited | Arts & recreation | 2015 |
| Monstaress Limited | Wholesale & retail | 2025 |
| Monsterfish Ltd | Administrative & support | 2007 |